From: Johan Hovold <johan@kernel.org>
Date: Thu, 21 Sep 2017 08:40:18 +0000 (-0300)
Subject: cx231xx-cards: fix NULL-deref on missing association descriptor
X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~8^2^2~101
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=40267d7a96c4e9a51a57603b9702c4cfe754b52e;p=linux-4.9.git

cx231xx-cards: fix NULL-deref on missing association descriptor

Make sure to check that we actually have an Interface Association
Descriptor before dereferencing it during probe to avoid dereferencing a
NULL-pointer.

Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver")

Cc: stable <stable@vger.kernel.org>     # 2.6.30
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name media-cx231xx-cards-fix-NULL-deref-on-missing-associ.patch
---

diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index be9e3335dcb7..921cf1edb3b1 100644
--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -1622,7 +1622,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 	nr = dev->devno;
 
 	assoc_desc = udev->actconfig->intf_assoc[0];
-	if (assoc_desc->bFirstInterface != ifnum) {
+	if (!assoc_desc || assoc_desc->bFirstInterface != ifnum) {
 		dev_err(d, "Not found matching IAD interface\n");
 		retval = -ENODEV;
 		goto err_if;